Aaron Swartz was determined to free up access to academic articles. He perceived an injustice in which scientific research lies behind expensive paywalls despite being funded by the taxpayer. The taxpayer ends up paying twice for the same research: once to fund it and a second time to read it.

The heart of the problem lies in the reputation system, which encourages scientists to put their work behind paywalls. The way out of this mess is to build new reputation metrics. The changes to reputation metrics in science that are underway are reflective of how reputation is measured online: Twitter has followers and retweets; GitHub has followers and forks; StackOverflow has reputation; Facebook has likes and comments; YouTube has view counts.

An ecosystem of startups is working on building these new reputation metrics in science, including my startup Academia.edu, as well as Mendeley and ResearchGate (other important players in the space are PLoS and Google Scholar). All three platforms have passed 2 million users and are growing fast. In three to four years, all the world’s scientists will be on one or all of these platforms...